The present invention relates to a method of continuously manufacturing compresses or drapes for single use, constituted by a plurality of superposed alternating layers of hydrophilic cotton gauze and of non-woven hydrophilic web, the outer layers being of hydrophilic cotton gauze. The invention also relates to a compress or drape obtained by the method.
Single use drapes of this type are used in particular in hospitals for surgical purposes, e.g. as a wall drape covering the edges of a wound after incision and before spreaders have been put into place. They can also be used as abdominal drapes on which viscera or intestinal loops can be laid out. If previously moistened, they can be used to protect an organ that is sensitive to drying out.
Drapes are known that are made of cotton, of polyester with cotton, or of polyester with microfiber, and which are washed and disinfected after each use, and then refolded, reconditioned, and resterilized, thus giving rise to a danger of accidental contamination in laundries during the handling of soiled drapes. Such drapes also suffer from the drawback of shedding particles of cotton fluff which can give rise to infections.
To mitigate those drawbacks, inherent to known drapes for multiple uses after reconditioning, French patent No. 2 724 838 and European patent application 0 702 9.38 A1 in the name of the Applicant propose a drape for single use made up a plurality of superposed alternating sheets of hydrophilic cotton gauze and of non-woven web. That drape is manufactured by means of a method that essentially comprises the following steps: on a single continuous sheet of hydrophilic cotton gauze there are placed two non-woven sheets each of width corresponding to one-third the width of the hydrophilic cotton gauze sheet so as to leave one-third of its width unoccupied; the multilayer strip is obtained by folding so that the hydrophilic cotton gauze forms the outer layers of the multilayer strip.
Unlike known products that are somewhat similar thereto, that drape, which is manufactured without using adhesive for assembling the various layers together, has the advantage of bringing the wound into contact with natural fiber that does not become shaggy, combined with the absorption capacity of a non-woven fiber as constituted, for example, by absorbent viscose and polypropylene, a polyester compound and viscose, a polyester, or a polyamide.
By associating differing materials, namely a woven material and a non-woven material, it is possible to combine the respective advantages of both of them: the woven material has strength that remains unchanged whether it is dry or wet, whereas a non-woven material is weaker when wet. In addition, the hydrophilic cotton gauze provides a xe2x80x9ccloth feelxe2x80x9d and its high strength in tension ensures that the finished product is strong. In contrast, the non-woven material has very high absorption capacity. Drapes of that type possess absorption capacity that is twice as large a conventional drape of woven material while still being very strong.
That type of material has been developed by the Applicant and gives complete satisfaction in use. However, to comply with economic imperatives, it is desirable to seek to simplify the method of manufacturing drapes of that type as proposed by the Applicant in the above-mentioned patent documents, in order to reduce the cost of manufacturing the product and make it more competitive.
Consequently, an object of the present invention is to provide a method of continuously manufacturing compresses and drapes of the above-described type associating two different materials, namely the hydrophilic cotton gauze and the non-woven web, which method is simpler to implement and makes it possible to reduce the cost of manufacturing the product.
To achieve those objects, the present invention proposes a method of continuous manufacture which comprises the following steps:
a single continuous multilayer strip or sheet is made by simultaneously paying out sheets or strips of hydrophilic cotton gauze and of non-woven web from payout spools or reels, which may be associated with at least one device for automatically adjusting the tension of the strips, said strips passing together via a motorized drive device prior to reaching stations for making up individual drapes;
continuous non-woven ribbons or bands are put into place on the longitudinal edges of the multilayer strip by being paid out from spools, said bands being folded around the longitudinal edges of the multilayer strip over the outer sheets to form a hems;
the ribbons or bands folded around the longitudinal edges of the multilayer strip are assembled in a bonding station by means of ultrasonic bonds passing through the folded-over branches of the band and through all of the layers of the multilayer strip;
individual drapes are cut transversely to length in a cutting station and optionally dust is sucked up by means of a suction device;
the cut of drape is taken up perpendicularly by a drive device; and
hem-forming ribbons or bands are placed around the transverse edges of the individualized drapes and are secured to said folded-over ribbons or bands by ultrasonic bonding.
In a preferred implementation of the invention, the sheets constituting the multilayer strip are assembled together and the ribbons or bands folded around the four edges of the drapes to form hems are fixed in place by ultrasonic bonding. Nevertheless, it is also possible to replace ultrasonic bonding by a stitching technique.
In order to ensure that the strips constituting the multilayer strip are properly paid out, it is advantageous, in accordance with the invention, to provide for the tension of the strips of hydrophilic cotton gauze to be obtained by traction exerted on said strips by a drive device and by braking the payout spools or reels, whereas the tension of the non-woven strip can be obtained after motor-driven payout from the corresponding spool or reel by means of a device for automatically adjusting the tension of said strip, which device is placed between the payout spool and the drive device, and because of the non-woven strip being driven by friction between the strips of hydrophilic cotton gauze, themselves driven by the drive device. It is also possible to provide a device for automatically adjusting the tension of the multilayer strip, which device is interposed between firstly the station for putting the longitudinal ribbons or bands into place and/or the bonding station, and secondly the station for cutting out the individual drapes.
According to another characteristic of the invention, it is advantageous to include an X-ray detectable thread in at least one of the hems of the drapes. To this end, a thread, e.g. of barium sulfate impregnated polyester, is placed along at least one of the longitudinal edges of the multilayer strip prior to or simultaneously with the ribbons or bands being put into place and being secured by ultrasonic bonding or by stitching. Naturally, it is also possible to integrate an X-ray detectable thread in analogous manner in at least one of the transverse hems of a drape.
In order to hold the drapes or the sheets making up the multilayer strip in place in a single unit and in order to prevent them from separating from one another and thus running the risk of damaging the drape, it is advantageous to make provision for a plurality of longitudinal lines of ultrasonic bonding or stitching to be applied, which lines should be distributed at uniform intervals over the entire width of the multilayer strip or of the drape, preferably before the band is put into place along the longitudinal edges thereof, and in any event before the strip is cut up into individual drapes.
The compress or drape for single use manufactured by the method of the invention is made up of a plurality of layers, preferably three layers, comprising, in alternation, hydrophilic cotton gauze and non-woven hydrophilic web, with the outer layers being of hydrophilic cotton gauze; the drape has its edges finished by ribbons or bands of non-woven web forming hems, secured to the component sheets by ultrasonic bonding or by stitching, and an X-ray detectable thread is included in at least one of the four hems, and in addition longitudinal lines of ultrasonic bonding or of stitching are provided that are spaced apart from one another and that are distributed over the entire width of the drape.